For example, Avionics Full Duplex Switching Ethernet (AFDX) is used for communication between aircraft systems, which is a conventional designation for ARINC Standard 664. This standard describes a network and the accompanying protocol for communication between aircraft systems.
In such AFDX networks, AFDX end systems are connected in a star topology by means of switches in point-to-multipoint connections (P2MP). To ensure redundancy, the network is duplicated. The network system thus encompasses a first network and a second network, which are built independently of each other. The data of the network end system are here output via two ports of the network end system to the independent networks.
In addition, the protocols High Availability Seamless Redundancy (HRS) and Parallel Redundancy Protocol (PRP) are used to ensure redundancy, in particular in networks of industrial and power plant automation. The latter are described in the IEC 62439-3 standard.